Obesity (or adipocity) is a multifactorial metabolic disorder caused from an imbalance between energy intake and expenditure that may have genetic and/or behavioral factors affecting the quantity and quality of food intake as well as lifestyle. It is characterized by increased body weight accompanied by an important deregulation of the adipose tissue function. Obesity is associated with a cluster of chronic and progressive diseases including type 2 diabetes, hyperinsulinemia, dyslipidemia, hepatic pathologies and inflammation among others. On the other hand, overweight is generally defined as having more body fat than is optimally healthy. Being overweight is a common condition, especially where food supplies are plentiful and lifestyles are sedentary.
In biology, adipose tissue or body fat or just fat is loose connective tissue composed mostly of adipocytes. In addition to adipocytes, adipose tissue contains the stromal vascular fraction (SVF) of cells including preadipocytes, fibroblasts, vascular endothelial cells and variety of immune cells (i.e. adipose tissue macrophages (ATMs)). Adipose tissue is derived from preadipocytes. Its main role is to store energy in the form of lipids, although it also cushions and insulates the body. Adipose tissue has in recent years been recognized as a major endocrine organ that produces hormones such as leptin, estrogen, resistin, and the cytokineTNFα. Adipose tissue can affect other organ systems of the body and may lead to disease. Obesity or being overweight in humans and most animals depends on the amount of body fat (adipose tissue). There are two types of adipose tissue, the white adipose tissue (WAT) and brown adipose tissue (BAT).
The main treatment for obesity consists mainly in the worlwide known slimming dieting and physical exercise. Diet programs may produce weight loss over the short term, but maintaining this weight loss is frequently difficult and often requires making exercise and a lower food energy diet a permanent part of a person's lifestyle. Among the known active principles indicated for the treatment of obesity orlistat (Xenical), is current widely available and approved for long term use. Weight loss however is modest with an average of 2.9 kg (6.4 lb) at 1 to 4 years and there is little information on how these drugs affect longer-term complications of obesity. In addition orlistat is associated with gastrointestinal side effects and concerns have been raised about negative effects on the kidneys. Two other medications are also available. Lorcaserin results in an average 3.1 kg weight loss (3% of body mass) greater than placebo over a year. A combination of phentermine and topiramate (Qsymia) is also somewhat effective. On the other hand, obesity is also faced by means of bariatric surgery (reducing the size of the stomach or by resecting and re-routing the small intestines to a small stomach pouch). Surgery for severe obesity is associated with long-term weight loss and decreased overall mortality. However, due to its cost and the risk of complications, researchers are searching for other effective yet less invasive treatments.
Reduction of body adipose tissue is also a cosmetic issue. For instance, there exist many cosmetical compositions with the aim of reducing fat stores in specific areas of the body (thigh, hips, and abdomen). As an example, the patent document EP1541127B1 discloses the use of modulators of aquaglyceroporin adipose (AQPap) in cosmetic compositions as slimming agents. The modulators are selected from coca powder extracts, sapogenins and lycopene in nanocapsules that stimulate AQPap activity, and compounds that enhances AQPap synthesis, such as aescin, complexes of phospholipids and retinoids. The composition may also comprise lypolitic slimming agents and/or lipogenesis inhibitor and/or adipocyte differentiation inhibitor. The lipolytic agent may be a phosphodiesterase inhibitor, a inhibitor of LDL or VLDL receptors, lipolytic peptides and lipolytic proteins.
Hepatic steatosis, also known as Fatty liver, or fatty liver disease (FLD), is a condition where large vacuoles of triglyceride fat accumulate in liver cells via the process of steatosis (i.e. abnormal retention of lipids within a cell). Despite having multiple causes, fatty liver can be considered a single disease that occurs worldwide in those with excessive alcohol intake and those who are obese (with or without effects of insulin resistance). Among these causes, hepatic steatosis is associated with alcohol or metabolic syndrome (diabetes, hypertension, obesity and dyslipidemia), but can also be due to any one of many causes. As for the diagnosis, most individuals are asymptomatic and are usually discovered incidentally because of abnormal liver function tests or hepatomegaly noted in unrelated medical conditions. Elevated liver enzymes are found in 50% of patients with simple steatosis. The serum alanine transaminase level usually is greater than the aspartate transaminase level in the nonalcoholic variant and the opposite in alcoholic FLD (AST:ALT more than 2:1). Currently, the treatment of fatty liver depends on its cause, and generally, treating the underlying cause will reverse the process of steatosis if implemented at an early stage.
Therefore, due to high prevalence of some of the above-mentioned diseases, and of the non-resolutive at all therapeutically approaches for them, it is noteworthy the need of much additional treatment approaches to face all those diseases in which an abnormal accumulation of fat is present in some animal tissues.